1. Technical Field
The present disclosure relates generally to robot arm assemblies and, more particularly, to a robot arm assembly.
2. Description of Related Art
A commonly used industrial robot includes a fixed base, a frame pivotally connected thereto about a first rotation axis, a lower arm, one end of which is pivotally connected to the frame about a second rotation axis, and an upper arm, one end of which is pivotally connected to the other end of the lower arm about a third rotation axis. An actuator, such as a welding device, a gripper or a cutting tool, is mounted at a distal end of the upper arm of the industrial robot to execute specific tasks. Generally, six axes are utilized to achieve maximum movement of the actuator.
In robots of this kind, each arm rotates around a rotation axis driven by a driving unit. Typically, the driving unit includes a motor mounted on the lower arm and a speed reducer coupled to the motor to transmit the movement of the motor to the upper arm. The speed reducer may be a high gear ratio gear, such as a harmonic gear reducer, a RV reducer (rotary vector reducer), or a planetary reducer. The motor and the speed reducer are arranged along the rotation axis of the arm, rendering the range along the rotation axis relatively large. Thus, the robots are not adept to work in a small room. In addition, a cost of the speed reducer is high, such that the robots generally have a high manufacturing cost.
Therefore, there is room for improvement within the art.